Why using Ipv6?

IPv4 has only about 4.3 billion addresses available—in theory, and we know that we don’t even get to use all of those. There really are only about 250 million addresses that can be assigned to devices. There are a lot of reports that give us all kinds of numbers, but all you really need to think about to convince yourself that I’m not just being an alarmist is the fact that there are about 6.5 billion people in the world today, and it’s estimated that just over 10 percent of that population is connected to the Internet, which means will run out of them, and it’s going to happen within a few years.

That statistic is basically screaming at us the ugly truth that based on IPv4’s capacity, every person can’t even have a computer—let alone all the other devices we use with them. I have more than one computer, and it’s pretty likely you do too. And I’m not even including in the mix phones, laptops, game consoles, fax machines, routers, switches, and a mother lode of other devices we use every day! So I think I’ve made it pretty clear that we’ve got to do something before we run out of addresses and lose the ability to connect with each other as we know it. And that "something" just happens to be implementing IPv6.

The problem of IPv4 address exhaustion was recognized in the early 1990s, when various experts made projections showing that if the increasing rate of the allotment of IPv4 addresses continued, the entire address space could be depleted in just a few short years. A newversion of IPknown in the development stage as IP Next Generation or IPng, and which is now IPv6was the proposed solution. But it was recognized that developing the new standards would take time, and that a short-term solution to IPv4 address depletion also was needed.

That short-term solution was Network Address Translation (NAT), which allows multiple hosts to share one or a few public IP addresses. Behind the NAT device, private IP addresses are used. NAT has been so successful in slowing IPv4 address depletion, and has become such a standard part of most networks, that to this day many still question the need for a new version of IP. But the widespread use of NAT has changed the open, transparent, peer-to-peer Internet into something much more like a huge collection of client-server networks. Users are seen as being connected around the "edge" of the Internet, and services flow out to them.

Although most of the IPv6 standards were completed years ago, it is only recently that serious interest in migrating from IPv4 to IPv6 has been shown. There are two fundamental drivers behind the growing recognition of the need for IPv6. The first is widespread vision of new applications using core concepts such as mobile IP, service quality guarantees, end-to-end security, grid computing, and peer-to-peer networking. NAT stifles innovation in these areas, and the only way to get NAT out of the way is to make public IP addresses abundant and readily available.

Benefits using Ipv6?

IPv6 includes the following enhancements over IPv4: ■ Expanded address space—IPv6 uses 128-bit addresses instead of the 32-bit addresses in IPv4.

■ Globally unique IP addresses—The additional address spaces allow each node to have a unique address and eliminate the need for NAT.

■ Support for labeling traffic flows—Instead of the type-of-service field in IPv4, IPv6 enables the labeling of packets belonging to a particular traffic class for which the sender requests special handling. This support aids specialized traffic, such as real-time video& traffic flow. There are several advantages to differentiating flows, from providing a finer-grained differentiated class-of-service treatment to ensuring, when balancing traffic loads across multiple paths, that packets belonging to the same flow are always forwarded over the same path to prevent possible reordering of packets. As of this writing, however, the complete specification of how to use the flow label field is still being debated, and routers currently ignore the field.

■ Mobility and security: Mobility and security help ensure compliance with mobile IP and IPsec standards functionality. Mobility enables people to move around in networks with mobile network devices—with many having wireless connectivity. The standard enables mobile devices to move without breaks in established network connections. Because IPv4 does not automatically provide this kind of mobility,You must add it with additional configurations. In IPv6, mobility is built in (any cast), which means that any IPv6 node can use it when necessary. IPsec is mandatory in IPv6. IPsec is enabled on every IPv6 node and is available for use. The availability of IPsec on all nodes makes the IPv6 Internet more secure. IPsec also requires keys for each party, which implies a global key deployment and distribution.